Why I can't reveal my active key ?

Words
89
Reading
1 min
Listen
Play
7y

Can someone please explain why I can't reveal my active key ?

I have 108 steem power and let's say I want to delegate 100, is that possible ?

When I try also to power down it telling me to leave there at least 5 steem and I do, but there is a transaction error anyway.

How many steem steem power i need to be able to delegate ? I don't want to power down, I need to delegate it to a project.

Maybe you gtg@gtg can explain ?